1. Field of the Invention
The present invention relates to a microscope and a dust treatment method for a microscope.
2. Description of the Related Art
Generally, microscopes, particularly, microscopes for educational use, are often used for a long term once purchased. Therefore, motes and dust enter inside from openings of a microscope over a long time, and as a result, such malfunctions as degradation of an observed image caused by dust accumulated on optical parts, or failures in operations caused by dust accumulated on a driving mechanism occur. Similarly, in microscopes for research use that are used in a research institute and the like or microscopes for inspection use that are used at a production site, specimens frequently changed. Therefore, motes and dust are likely to be accumulated therein, and similar failures occur. Furthermore, in recent years, study subjects have become increasingly minute, and microscopy using a laser has been conducted to obtain high-powered and high resolution images. Because such microscopy requires a difficult observation condition, it is severely affected by motes and dust, and therefore, extreme caution is required.
To specifically explain conventional malfunctions, a schematic side view of a conventional upright microscope is shown in FIG. 6. An incident-light-illumination optical path Xr and a transmitting-illumination optical path Xt are arranged in a main body 1, and lamp houses 11r and 11t are provided for the optical paths Xr and Xt, respectively. To the incident-light-illumination optical path Xr, an optical-path switching unit 1a that can switch among bright-field microscopy, dark-field microscopy, DIC microscopy, and the like is provided, and by pushing in and pulling out a knob 1b in a direction of front and back of a drawing sheet, the microscopy method can be switched by a not shown guide mechanism. Arranged at an upper portion of the main body 1 is a trinocular barrel 2 provided with an eye lens 3 and a TV adaptor 12 to which a TV camera 13 is attached. By pushing in and puling out, in the direction of front and back of the drawing sheet, a knob 2b of an optical-path switching unit 2a that can switch between an observation optical axis X of a binocular portion and an observation optical axis Xc of a trinocular portion, the observation optical path is switched by a not shown guide mechanism. Moreover, arranged on the observation optical path X are a revolver 5 provided with an objective lenses 6, a stage 7 that is mounted on a stage receiver 10 arranged so as to be movable in a vertical direction by rotation of a handle 1c of the main body 1, and a capacitor 9. The capacitor 9 is structured so that optical members such as a phase difference ring can be selectively arranged on the observation optical axis X by a not shown rotating mechanism. Thus, an observer 4 can observe a specimen 8 by a desired microscopy method.
However, in the main body 1, an opening 1d to which an illumination filter is inserted, an FS adjusting hole 1e, and an AS adjusting hole 1f are present, and exterior motes and dust enter the inside of the main body 1. Entered dust scatters in various directions as shown by arrows D1 to D6, to adhere to various optical parts such as an objective lens, and a driving mechanism such as the optical-path switching unit 1a. In addition, optical path switching by the optical-path switching unit 1a causes wear of metal and resin of the not shown guide mechanism. Accordingly, metal powder and resin powder fall in a direction of the objective lenses 6 as indicated by an arrow D7. Furthermore, when the stage receiver 10 is moved in a vertical direction by way of a rack-and-pinion mechanism by rotation of a handle 1c, metal powder or resin powder falls as indicated by an arrow D8.
Similarly, in the trinocular barrel 2, powder due to wear caused by switching performed by the optical-path switching unit 2a falls on an imaging lens as indicated by an arrow D9. Also inside the capacitor 9, powder due to wear occurs and adheres to optical parts, although not illustrated. Entrance of exterior dust can be prevented to some extent by closing openings. However, it is difficult to completely shut portions to which the user puts in an optical part.
For malfunctions due to dirt on an optical part, a structure capable of easily cleaning a dust filter has been proposed (for example, Japanese Patent Laid-Open Publication No. H8-179220). A technique disclosed in Japanese Patent Laid-Open Publication No. H8-179220 facilitates cleaning work by newly arranging a dust filter for cleaning because cleaning of a dust filter arranged near a CCD is difficult.
For malfunctions due to dirt on a driving mechanism, there has been a proposal in which a mechanism section of a stage is arranged under a stage floor to avoid adverse effects of dust on the stage (for example, Japanese Patent Laid-Open Publication No. 2005-157383).
However, in the one disclosed in Japanese Patent Laid-Open Publication No. H8-179220, although cleaning work is facilitated, complicated disassembling work is still required. In addition, even such work is still required, parts that are not essential for the function such as a dust filter, a tube for attachment and detachment, and a holding ring are required, and, as a result, cost increases. Therefore, it cannot be regarded as an enough improvement.
Furthermore, in the one disclosed in Japanese Patent Laid-Open Publication No. 2005-157383, measures against dust that falls from the mechanism section of the stage is not considered, and adhesion of dust on a focusing mechanism or a capacitor arranged at a lower portion of the stage cannot be avoided. Therefore, complicated cleaning is required for such mechanism and the like.